Enhance DaliCloudBridge: add gateway settings handler and support for gateway configuration messages

Signed-off-by: Tony <tonylu@tony-cloud.com>

include/gateway_cloud.hpp

@@ -6,6 +6,7 @@
 #include <atomic>
 #include <functional>
 #include <string>
+#include <string_view>
 #include <vector>
 
 #ifdef ESP_PLATFORM
@@ -36,6 +37,9 @@ struct GatewayCloudConfig {
 class DaliCloudBridge {
  public:
   using CemiDownlinkHandler = std::function<bool(const uint8_t* data, size_t len)>;
+  /// Handles gateway-level configuration messages received on the normal MQTT
+  /// downlink topic and returns the JSON acknowledgement for the up topic.
+  using GatewaySettingsHandler = std::function<std::string(std::string_view request)>;
 
   explicit DaliCloudBridge(DaliComm& comm);
 
@@ -46,6 +50,7 @@ class DaliCloudBridge {
   DaliBridgeEngine& bridge() { return bridge_; }
   const DaliBridgeEngine& bridge() const { return bridge_; }
   void setCemiDownlinkHandler(CemiDownlinkHandler handler);
+  void setGatewaySettingsHandler(GatewaySettingsHandler handler);
 
   bool publishStatus(const std::string& status);
   bool publishRegister(const std::string& payloadJson);
@@ -81,6 +86,7 @@ class DaliCloudBridge {
   DaliBridgeEngine bridge_;
   GatewayCloudConfig config_;
   CemiDownlinkHandler cemi_downlink_handler_;
+  GatewaySettingsHandler gateway_settings_handler_;
   std::atomic<bool> connected_{false};
   std::atomic<bool> lte_uart_started_{false};
   std::atomic<bool> lte_uart_stop_requested_{false};

src/gateway_cloud.cpp

@@ -339,6 +339,10 @@ void DaliCloudBridge::setCemiDownlinkHandler(CemiDownlinkHandler handler) {
   cemi_downlink_handler_ = std::move(handler);
 }
 
+void DaliCloudBridge::setGatewaySettingsHandler(GatewaySettingsHandler handler) {
+  gateway_settings_handler_ = std::move(handler);
+}
+
 bool DaliCloudBridge::publishStatus(const std::string& status) {
   std::string payload = "{\"type\":\"status\",\"status\":\"" + status + "\"}";
   return publishJSON(topicStatus(), payload);
@@ -571,6 +575,16 @@ bool DaliCloudBridge::handleDownlink(const std::string& payload) {
     return false;
   }
 
+  const std::string type = toString(cJSON_GetObjectItemCaseSensitive(root, "type"));
+  if (type == "gatewaySettingsGet" || type == "gatewaySettingsSet") {
+    const std::string response = gateway_settings_handler_
+                                     ? gateway_settings_handler_(payload)
+                                     : "{\"type\":\"gatewaySettings\",\"status\":\"error\","
+                                       "\"error\":\"gateway settings are unavailable\"}";
+    cJSON_Delete(root);
+    return !response.empty() && publishJSON(topicUp(), response);
+  }
+
   DaliBridgeRequest request;
   const cJSON* seqItem = cJSON_GetObjectItemCaseSensitive(root, "seq");
   if (seqItem == nullptr) seqItem = cJSON_GetObjectItemCaseSensitive(root, "sequence");